Current and novel approaches in the pharmacological treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most lethal malignant tumours worldwide. The mortality-to-incidence ratio is up to 91.6% in many countries, representing the third leading cause of cancer-related deaths. Systemic drugs, including the multikinase inhibitors sorafenib and lenvatinib, are first-line drugs used in HCC treatment. Unfortunately, these therapies are ineffective in most cases due to late diagnosis and the development of tumour resistance. Thus, novel pharmacological alternatives are urgently needed. For instance, immune checkpoint inhibitors have provided new approaches targeting cells of the immune system. Furthermore, monoclonal antibodies against programmed cell death-1 have shown benefits in HCC patients. In addition, drug combinations, including first-line treatment and immunotherapy, as well as drug repurposing, are promising novel therapeutic alternatives. Here, we review the current and novel pharmacological approaches to fight HCC. Preclinical studies, as well as approved and ongoing clinical trials for liver cancer treatment, are discussed. The pharmacological opportunities analysed here should lead to significant improvement in HCC therapy.

The Combination Sorafenib-raloxifene-loratadine as a Novel Potential Therapeutic Approach Against Human Liver Cancer.

BACKGROUND/AIM: Liver cancer is one of the malignancies with the highest mortality-to-incidence ratio worldwide. Therefore, novel therapeutic approaches are urgently needed. Combination therapy and drug repurposing can improve the response of the patients to therapy in several cancers. The aim of the present study was to merge these two strategies and evaluate whether the two-drug- or three-drug- combination of sorafenib, raloxifene, and loratadine improves the antineoplastic effect on human liver cancer cells in comparison to the single-drug effect. MATERIALS AND METHODS: The human liver cancer cell lines HepG2 and HuH7 were studied. The effect of sorafenib, raloxifene, and loratadine on the metabolic activity was determined using the MTT assay. The inhibitory concentrations (IC20 and IC50) were calculated from these results and used in the drug-combination experiments. Apoptosis and cell survival were studied by flow cytometry and using the colony formation assay, respectively. RESULTS: In both cell lines, sorafenib, raloxifene, and loratadine in two-drug and three-drug combinations significantly reduced metabolic activity and significantly increased the percentage of apoptotic cells compared to the single-drug effect. In addition, all the combinations significantly reduced the colony-forming capacity in the HepG2 cell line. Surprisingly, the effect of raloxifene on apoptosis was similar to that observed using the combinations. CONCLUSION: The triple combination sorafenib-raloxifene-loratadine may be a novel promising approach in the treatment of liver cancer patients.

The Phytochemical α-Mangostin Inhibits Cervical Cancer Cell Proliferation and Tumor Growth by Downregulating E6/E7-HPV Oncogenes and KCNH1 Gene Expression.

Cervical cancer is the fourth most common cancer among women worldwide. The main factor associated with the onset and progression of this neoplasia is the human papillomavirus (HPV) infection. The HPV-oncogenes E6 and E7 are critical drivers of cellular transformation, promoting the expression of oncogenes such as KCNH1. The phytochemical α-mangostin (AM) is a potent antineoplastic and antiviral compound. However, its effects on HPV oncogenes and KCNH1 gene expression remain unknown. This study evaluated the effects of AM on cell proliferation, cell cycle distribution and gene expression, including its effects on tumor growth in xenografted mice. AM inhibited cell proliferation in a concentration-dependent manner, being the most sensitive cell lines those with the highest number of HPV16 copies. In addition, AM promoted G1-cell cycle arrest in CaSki cells, while led to cell death in SiHa and HeLa cells. Of interest was the finding of an AM-dependent decreased gene expression of E6, E7 and KCNH1 both in vitro and in vivo, as well as the modulation of cytokine expression, Ki-67, and tumor growth inhibition. On these bases, we suggest that AM represents a good option as an adjuvant for the treatment and prevention of cervical cancer.

Eag1 Gene and Protein Expression in Human Retinoblastoma Tumors and its Regulation by pRb in HeLa Cells.

Retinoblastoma is the most common pediatric intraocular malignant tumor. Unfortunately, low cure rates and low life expectancy are observed in low-income countries. Thus, alternative therapies are needed for patients who do not respond to current treatments or those with advanced cases of the disease. Ether à-go-go-1 (Eag1) is a voltage-gated potassium channel involved in cancer. Eag1 expression is upregulated by the human papilloma virus (HPV) oncogene E7, suggesting that retinoblastoma protein (pRb) may regulate Eag1. Astemizole is an antihistamine that is suggested to be repurposed for cancer treatment; it targets proteins implicated in cancer, including histamine receptors, ATP binding cassette transporters, and Eag channels. Here, we investigated Eag1 regulation using pRb and Eag1 expression in human retinoblastoma. The effect of astemizole on the cell proliferation of primary human retinoblastoma cultures was also studied. HeLa cervical cancer cells (HPV-positive and expressing Eag1) were transfected with RB1. Eag1 mRNA expression was studied using qPCR, and protein expression was assessed using western blotting and immunochemistry. Cell proliferation was evaluated with an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. RB1 transfection down-regulated Eag1 mRNA and protein expression. The human retinoblastoma samples displayed heterogeneous Eag1 mRNA and protein expression. Astemizole decreased cell proliferation in primary retinoblastoma cultures. Our results suggest that Eag1 mRNA and protein expression was regulated by pRb in vitro, and that human retinoblastoma tissues had heterogeneous Eag1 mRNA and protein expression. Furthermore, our results propose that the multitarget drug astemizole may have clinical relevance in patients with retinoblastoma, for instance, in those who do not respond to current treatments.

An aqueous extract of Stevia rebaudiana variety Morita II prevents liver damage in a rat model of cirrhosis that mimics the human disease.

INTRODUCTION AND AIM: Stevia has exhibited antioxidant, antihyperglycemic, antihypertensive and anti-inflammatory properties in several in vivo and in vitro models. The objective of this study was to investigate the ability of an aqueous extract of stevia (AES) to prevent experimental cirrhosis in rats and to explore its mechanism of action. MATERIALS AND METHODS: Liver cirrhosis was induced by administering carbon tetrachloride (CCl4) (400mg/kg by i.p. injection 3 times a week for 12 weeks); AES was administered (100mg/kg by gavage daily) during the CCl4 treatment. Fibrosis was evaluated with histological, biochemical and molecular approaches, and liver damage was assessed with standardized procedures. The profibrotic pathways were analyzed by western blotting, qRT-PCR and immunohistochemistry. RESULTS AND CONCLUSIONS: Chronic CCl4 administration increased nuclear factor kappa B (NF-κB) and proinflammatory cytokine production as well as oxidative parameters such as lipid peroxidation and 4-hydroxynonenal levels, whereas GSH and nuclear factor-E2-related factor 2 (Nrf2) levels were decreased. CCl4 induced profibrogenic mediator expression, hepatic stellate cell (HSC) activation and, consequently, extracellular matrix production. AES exhibited antioxidant, anti-inflammatory and antifibrotic properties, probably because of its capacity to induce Nrf2 expression, reduce NF-κB expression and block several profibrogenic signaling pathways, subsequently inhibiting HSC activation and preventing fibrosis induced by chronic CCl4 administration.

Stevia rebaudiana tea prevents experimental cirrhosis via regulation of NF-κB, Nrf2, transforming growth factor beta, Smad7, and hepatic stellate cell activation.

Stevia has been shown to prevent oxidative stress and inflammation in carbon tetrachloride­induced cirrhosis models. This study aimed to investigate the ability of an aqueous extract of stevia (AES) to prevent thioacetamide (TAA)­induced cirrhosis in rats and to explore its mechanism of action. Liver cirrhosis was established by administering TAA (200 mg/kg by i.p. injections three times a week for 10 weeks); AES was administered (100 mg/kg by gavage daily) during the TAA treatment. Liver damage and fibrosis were evaluated, and the profibrotic pathways were analyzed by western blotting and immunohistochemistry. TAA increased nuclear factor kappa B (NF­κB) and pro­inflammatory cytokine production, as well as the malondialdehyde and 4­hydroxynonenal levels, whereas the glutathione/glutathione disulfide and nuclear factor­E2­related factor 2 (Nrf2) levels were decreased. Moreover, TAA increased collagen production, hepatic stellate cell (HSC) activation, and expression of profibrogenic mediators. TAA­treated rats that had been exposed to Mn2+ exhibited altered striatal dopamine turnover, indicating hepatic encephalopathy. AES partially or completely prevented all of these effects. AES showed antioxidant, anti­inflammatory, and antifibrotic properties, probably because of its capacity to induce Nrf2 expression, reduce NF­κB expression, and block several profibrogenic signaling pathways, subsequently inhibiting HSC activation and preventing fibrosis and dopamine turnover.

One pot phytosynthesis of gold nanoparticles using Genipa americana fruit extract and its biological applications.

In this article, rapid one pot synthesis of gold nanoparticles (GNPs) using an eco-friendly extract of Genipa americana L. fruit is described. Electrospray ionization mass spectrometry (ESI-MS) and Fourier transform infrared (FTIR) spectroscopic studies demonstrated that small molecules such as genipin, genipaol, geniposide and ranolazine can act as reducer as well as stabilizers. The monodispersed, spherical GNPs were further characterized by UV-vis spectroscopy at λmax=535 nm, transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray diffraction (XRD) analysis. This synthetic approach offers a greener and alternate route to the preparation of GNPs free from toxic chemical components and stable for 6-7 months under room temperature. The green synthesized GNPs showed weak antioxidant efficacy against 1,1-diphenyl-2-picrylhydrazyl and no cytotoxicity against A-549 and HeLa human cancer cell lines, from lung and cervix. This study opens a new industrial scope of G. americana fruit in nanoscience and as surface modified GNPs can be developed into a successful drug carrier for future pharmaceutical products.

Astemizole synergizes calcitriol antiproliferative activity by inhibiting CYP24A1 and upregulating VDR: a novel approach for breast cancer therapy.

BACKGROUND: Calcitriol antiproliferative effects include inhibition of the oncogenic ether-à-go-go-1 potassium channel (Eag1) expression, which is necessary for cell cycle progression and tumorigenesis. Astemizole, a new promising antineoplastic drug, targets Eag1 by blocking ion currents. Herein, we characterized the interaction between calcitriol and astemizole as well as their conjoint antiproliferative action in SUM-229PE, T-47D and primary tumor-derived breast cancer cells. METHODOLOGY/PRINCIPAL FINDINGS: Molecular markers were studied by immunocytochemistry, Western blot and real time PCR. Inhibitory concentrations were determined by dose-response curves and metabolic activity assays. At clinically achievable drug concentrations, synergistic antiproliferative interaction was observed between calcitriol and astemizole, as calculated by combination index analysis (CI <1). Astemizole significantly enhanced calcitriol's growth-inhibitory effects (3-11 folds, P<0.01). Mean IC(20) values were 1.82 ± 2.41 nM and 1.62 ± 0.75 µM; for calcitriol (in estrogen receptor negative cells) and astemizole, respectively. Real time PCR showed that both drugs alone downregulated, while simultaneous treatment further reduced Ki-67 and Eag1 gene expression (P<0.05). Astemizole inhibited basal and calcitriol-induced CYP24A1 and CYP3A4 mRNA expression (cytochromes involved in calcitriol and astemizole degradation) in breast and hepatoma cancer cells, respectively, while upregulated vitamin D receptor (VDR) expression. CONCLUSIONS/SIGNIFICANCE: Astemizole synergized calcitriol antiproliferative effects by downregulating CYP24A1, upregulating VDR and targeting Eag1. This study provides insight into the molecular mechanisms involved in astemizole-calcitriol combined antineoplastic effect, offering scientific support to test both compounds in combination in further preclinical and clinical studies of neoplasms expressing VDR and Eag1. VDR-negative tumors might also be sensitized to calcitriol antineoplastic effects by the use of astemizole. Herein we suggest a novel combined adjuvant therapy for the management of VDR/Eag1-expressing breast cancer tumors. Since astemizole improves calcitriol bioavailability and activity, decreased calcitriol dosing is advised for conjoint administration.